Effects of cadmium (Cd) on fungal richness, diversity, and community structure of Haplic Cambisols and inference of resistant fungal genera.

Abstract

Cadmium (Cd) is one of the most toxic and widely distributed pollutants in mining sites of Northeast China, and how Cd contamination may affect the fungal characteristics of the zonal Haplic Cambisols is still unknown. The study aims to investigate the richness and diversity of fungal community in Haplic Cambisols in response to Cd treatments and to infer Cd-resistant fungal genera. Haplic Cambisol was treated with different concentrations of CdCl2·2.5H2O solution (0mgkg-1, 1mgkg-1, 5mgkg-1, 25mgkg-1, and 50mgkg-1, expressed as CK, T1, T2, T3, and T4, respectively), and fungal community was analyzed by high-throughput sequencing technology at 30days, 60days, or 80days after Cd treatment (expressed as d30, d60, and d80, respectively). The results showed that Cd treatment usually increased the richness and diversity indices, the variation of diversity index under different Cd concentrations was not obvious, and different Cd incubation times had an inhibitory effect on fungal richness, but the diversity first increased and then decreased. Besides, Ascomycota and Mortierellomycota having the highest abundance in Haplic Cambisols showed the most pronounced changes under Cd treatment. Accordingly, Cd-resistant fungi were also found, such as Aspergillus, Fusarium, Penicillium, and Trichoderma, especially Aspergillus, which had relatively high abundance. The results obtained in this study had potentially significant findings for soil biodiversity and Cd bioremediation.